CHINESE JOURNAL OF POLYMER SCIENCE
·
2024
·
IF 4.1
Zhang Xin-Rao,Wang Fu-Shan,Wang Xin,Gao Yan,Zhang Hong-Xing,Liu Zhi-Qin,Feng Jia-Chun
Although Ziegler-Natta (Z-N) polyolefins have been widely used as raw materials to produce pharmaceutical or food packaging, the migration of acid scavengers, an additive usually introduced in Z-N polyolefins, from the packaging to its contents has not been reported. In this work, the migration of the two most used acid scavengers, calcium stearate (CaSt 2 ) and zinc stearate (ZnSt 2 ), from a Z-N polypropylene random copolymer (PPR) into water during autoclaving at 121 °C were comparatively investigated. It was found that, for PPR plates containing 0.1 wt% CaSt 2 or ZnSt 2 (PPR-0.1CaSt 2 , PPR-0.1ZnSt 2 , respectively), the concentration of migrated calcium ion into water increased with autoclaving time, while that of zinc ion was much lower at same treatment durations and did not show a significant increase with treatment time. Interestingly, after removing all plates and acidification treatment, a considerable amount of stearic acid was detected in sterilized water for PPR-0.1ZnSt 2 , but no such significant stearic acid was detected in sterilized water for PPR-0.1CaSt 2 . Based on the structural evolution of the two soaps upon heating, possible mechanisms for the different migration behavior of CaSt 2 and ZnSt 2 from PPR into water during autoclaving treatment were proposed. Our results suggest that the migration issue of acid scavengers is worthy of attention in pharmaceutical packaging materials produced from Z-N polyolefins.
研究领域:
材料科学
·
食品科学
·
药学
✓ 已验证
DOI
高影响因子
Food & Function
·
2022
·Vol. 13
·期 9
·5317-5326
·
IF 6.317
Zipeng Liu,Ling Chen,Bo Zheng
The nutritional design of personalized starchy foods has become a research hotspot in the field of food science. Driven by the immense functional and nutritional implications of starch–lipid binary interactions, this study is aimed at designing starch digestibility by controlling the interaction between starch and glycerol monostearate (GMS)/stearic acid (SA) using a hot-extrusion 3D printing (HE-3DP) environment. The results indicated that the thermal shear force in the HE-3DP environment promoted hydrophobic interactions between starch and lipids, forming a V-type starch–lipid complex with a compact and ordered structure, thus enhancing enzymatic resistance. Compared with GMS, SA with linear hydrophobic chains was inclined to compound with starch to form a more ordered structure. Interestingly, the slowly digestible starch (SDS) and resistant starch (RS) content reached 25.06% when the added SA content was 10%. Besides, correlations between the structural parameters and digestibility were established, which provided crucial information for designing nutritional starchy food systems using HE-3DP.
研究领域:
食品科学
·
营养学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2021
·
IF 4.539
Heliang Du,Xiaoyong Wang
The gel-like phase constructed by fatty acid compounds is a kind of fascinating soft matters but its structural characteristics have not been fully understood. This work has investigated the crystalline structures and formation mechanism of gel-like phase containing potassium stearate (KS), stearic acid (SA), and water at 80% neutralization degree. The crystalline fibers are observed in the gel-like samples of KS-SA-water on the polarized optical microscopy . X-ray diffraction measurement demonstrates that there are two isolate types of lamellar crystallites of KS and KS-SA complexes instead of the mixed crystallites in KS-SA-water samples. While KS crystallites have shorter Bragg spacing and tilted angle than the crystallites of KS-SA complexes, it is found that the solvent of water does not penetrate in the interlayer of two kinds of crystallites. The dynamic rheology measurement suggests the strong elasticity of KS-SA-water samples, which indicates the network structure formed by the lamellar crystalline fibers entrapping water. The addition of glycerol does not affect the crystalline structures of KS-SA-water samples, but significantly increase the values of storage modulus and melting enthalpy . This result suggests that the added glycerol can promote the strength of the hydrogen bonding between the solvent and crystalline fibers in the network structure of KS-SA-water samples. These findings provide new insights to the structural properties of gel-like phase of fatty acid compounds, which are importantly helpful for controlling their structure and functions.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2022
·
IF 4.432
Xinrao Zhang,Fuqing Wei,Zhuoni Wang,Guangquan Li,Shiyuan Yang,Jiachun Feng
Zinc stearate (ZnSt 2 ) and calcium stearate (CaSt 2 ) are two kinds of extensively used additives in polymer industry. However, the selection principle of the two soaps in different polyolefins is still unclear. To establish the action mechanism of these soaps in polyolefins application, the understanding of the exact structures when they play roles is prerequisite. In this work, considering that these additives play their roles during the melt processing of polyolefin, in which the structure may be different with their as-received states, the structures and evolution behavior of the two soaps in a polyolefin melt upon heating and cooling were systematically explored. It was found that the two soaps exhibited different dispersed structures and evolution behavior in the polypropylene random copolymer (PPR). The ZnSt 2 in PPR presented microcrystal at low temperatures and dissociated into ionic clusters during heating, and then gradually aggregated and recrystallized upon cooling; while the CaSt 2 in PPR exhibited vitreous agglomerates with lamella ordered structure at low temperatures and transformed to diverse colloidal liquid crystal aggregates during heating, and then gradually reassembled to vitreous agglomerates in cooling process. At concentration closed to practical application (about 1000 ppm or less), ZnSt 2 in molten PPR dispersed in form of ionic clusters like closed small molecules, whereas CaSt 2 in PPR melt presented weakly ordered aggregates. These findings provided an important foundation for building up the well-defined relationship between the structure and performance of these soaps in polyolefins.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Cleaner Production
·
2018
·
IF 5.651
Shangde Sun,Gaoshang Wang,Ping Wang
Monoricinolein (MRO) and diricinolein (DRO) were renewable and biodegradable lubricants . In this paper, MRO and DRO were prepared by the novel cleaner enzymatic glycerolysis of castor oil (CO) in solvent-free system. Three commercial immobilized lipases (Novozym 435, Lipozyme RM IM and Lipozyme TL IM) were screened and compared, and Novozym 435 showed the best catalysis performance among the tested lipases. Effects of reaction variables (reaction pressure, reaction time, temperature, enzyme load, substrate ratio and water content) on the enzymatic glycerolysis of CO were investigated. High conversion of CO (92.48 ± 1.02%) and the maximum bio lubricants yields (54.47 ± 0.58% MRO and 38.01 ± 0.50% DRO) were achieved under the following conditions: enzyme load 5% (w/w, based on the total mass), CO/glycerol ratio at 1:6, 90 °C, and 3 h. The activation energies (Ea) for CO conversion and the formation of MRO and DRO were calculated as 33.75 kJ/mol, 22.26 kJ/mol and 24.37 kJ/mol, respectively, and the process showed high selectivity toward the formation of MRO. Reaction kinetic agreed with the ping-pong Bi-Bi mechanism with the inhibition of CO, and the kinetic values ( V max , K m ′ and K IA ) were 0.0946 mol/(L·min), 1.6704 mol/L, and 0.89 mol/L, respectively.
研究领域:
生物化学
·
可再生资源工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Ningning Bai,Qing Li,Hongzhou Dong,Cui Tan,Peng Cai,Lan Xu
Self-recovering superhydrophobic coatings (SHCs) have drawn much attention in recent years because of their unique self-recovering properties and potential industrial applications. In this study, self-recovering SHCs based on recovery of structural damage have been successfully fabricated by spraying the mixture of polymethylmethacrylate/zinc stearate/stearic acid. The SHCs display a static contact angle (CA) of 158°, a sliding angle (SA) of 1° and exhibit a rough structure as shown in the SEM images. By acid rain (pH ≈ 3.5) scouring, the coatings maintain CA of 134° and high adhesion due to the broken morphology. Interestingly, the coatings restored superhydrophobicity after immersion in water for several minutes. Furthermore, the SHCs exhibit good long-term stability, water-durability and UV-durability, adapting to out-door environment. Above all, the coatings are environmental, low cost and can be quickly coated on various large-scale substrates, which will widen their practical applications.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
Particuology
·
2024
·
IF 4.1
Ming Zhou
This work investigates the flow and agglomeration behaviors of battery grade Li 2 CO 3 powder and the influence of stearic acid surface modification. The degree of agglomeration is directly related to the uniformity of Li 2 CO 3 and its powder mixtures. According to the Chinese National Nonferrous Metal Industry Standard, battery grade Li 2 CO 3 powder has D 50 equal to 3–8 μm which belongs to a micron-sized superfine powder. Therefore, with the extension of storage time, the serious agglomeration phenomenon occurs due to the large specific surface area and rough and irregular powder particles. The Hausner ratio (HR) of the unmodified sample increases from 1.14 to 1.41, and the corresponding flowability is classified as good to poor. Instead, among samples with doping stearic acid, the optimum amount of it is 0.10 wt% which exhibits an extremely stable HR value from 1.14 to 1.16. Meanwhile, after 156 days, the repose angle (AR) obtained for samples without surface modification and using 0.10 wt% stearic acid are calculated to be 49° and 28°, respectively. Based on the values of HR and AR, the flowability of the unmodified sample is poor while the sample modified with 0.10 wt% of stearic acid still maintain excellent powder flow property. Moreover, The LiMn 2 O 4 cathode material synthesized from modified Li 2 CO 3 powder with a stearic acid content of 0.10 wt% exhibits good crystallinity and comparable electrochemical performance to that prepared by commercial Li 2 CO 3 . These results indicate that stearic acid has the potential to be an ideal modifier for battery grade Li 2 CO 3 powder that needs to be kept for a long time.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2025
·
IF 8
Juncheng Wen,Yan Wan,Yingzi Yang
Most durability issues in cement-based materials stem from water intrusion, which can be mitigated by hydrophobic materials with excellent waterproofing properties. This study proposes a green wet chemical method using stearic acid (SA) and waste glass powder (WGP) to synthesize hydrophobic WGP (HWGP). The effect of SA dosage on the water contact angle of HWGP was investigated, and the optimal SA dosage for preparing HWGP was determined through TG analysis. XRD, FTIR, XPS, and TEM tests revealed the synthesis mechanism of HWGP. The effects of HWGP on mortar's mechanical properties, water and frost resistance were also studied, and the optimal dosage of HWGP for preparing hydrophobic mortar was determined. The results show that 8 % SA is optimal for preparing HWGP, and its water contact angle is 132.2°. The synthesis occurs through reactions between SA and Na + , Ca 2+ , and Si-OH groups, with the long carbon chains of SA grafted onto WGP, forming a hydrophobic layer about 4 nm thick. As HWGP content increases, compressive strength initially increases and then decreases, while water and frost resistance improve significantly. The optimal dosage for preparing hydrophobic mortar is 15 % HWGP, where compressive strength decreases by only 6.9 %, flexural strength increases by 12.5 %, and water contact angle increases by 91.2°. Additionally, initial and secondary water absorption rates decrease by 79.4 % and 92.2 %, respectively, total water absorption amount over 8d decreases by 64.9 %, and frost resistance improves by 70.9 %.
研究领域:
建筑材料
·
化学工程
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 8
·1887
·
IF 5
Hui Fang,Guifeng Li,Kai Wang,Fangjuan Wu
This study investigates the effect of adding stearic acid (SA) on the thermal conductivity of polyamide 6 (PA6)/boron nitride (BN) composites. The composites were prepared by melt blending, and the mass ratio of PA6 to BN was fixed at 50:50. The results show that when the SA content is less than 5 phr, some SA is distributed at the interface between BN sheets and PA6, which improves the interface adhesion of the two phases. This improves the force transfer from the matrix to BN sheets, promoting the exfoliation and dispersion of BN sheets. However, when the SA content was greater than 5 phr, SA tends to aggregate and form separate domains rather than being dispersed at the interface between PA6 and BN. Additionally, the well-dispersed BN sheets act as a heterogeneous nucleation agent, significantly improving the crystallinity of the PA6 matrix. The combination of good interface adhesion, excellent orientation, and high crystallinity of the matrix leads to efficient phonon propagation, resulting in a significant improvement in the thermal conductivity of the composite. The highest thermal conductivity of the composite is achieved when the SA content is 5 phr, which is 3.59 W m−1K−1. The utilization of a composite material consisting of 5phr SA as the thermal interface material displays the highest thermal conductivity, and the composite also demonstrates satisfactory mechanical properties. This study proposes a promising strategy for the preparation of composites with high thermal conductivity.Keywords:thermal conductivity;polyamide;boron nitride;stearic acid
研究领域:
材料科学
·
热管理技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2025
·Vol. 17
·期 5
·667
·
IF 4.9
Jipeng Dou,Yong Xie,Rui Chen,Yan Qin
Stearic acid was used to modify the surface of a mixed flame-retardant powder consisting of aluminum hydroxide and ammonium polyphosphate by an uneven nucleation method, aiming to improve its dispersion in a vinyl resin matrix. This study investigated the effect of stearic acid dosage on the powder’s surface modification, characterized by infrared spectroscopy, activation degree, and laser particle size distribution. The dispersion of the modified powder in the resin matrix was evaluated by measuring the system viscosity, scanning electron microscopy (SEM) images, and bending performance. The results indicated that when the stearic acid content was 1%, the powder exhibited the best overall coating effect, with a uniform particle size distribution and an activation degree of 73.6%. After the composite material was added to the resin, the system viscosity was 923 mPa·s, and SEM images showed good dispersion of the powder in the resin matrix. The cured resin demonstrated a bending strength of 41.86 MPa. However, the flame retardancy slightly decreased, with the limiting oxygen index (LOI) dropping from 24.6% for the unmodified sample to 24.0%. When the stearic acid content exceeded 1%, the powder’s particle size increased dramatically. Although the activation degree also increased, the improvement was not significant. The addition of the powder to the resin resulted in a higher system viscosity, and the flame retardancy deteriorated sharply, with the vertical burning rating dropping from FV-1 to FV-2. Considering flame retardancy, mechanical properties, and processing performance, the composite material with 1% stearic acid demonstrated the best overall performance.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE AMERICAN OIL CHEMISTS SOCIETY
·
2017
·Vol. 94
·期 9
·1153-1164
·
IF 1.421
Yang Shu,Li Guode,Saleh Ahmed S. M.,Yang Hongli,Wang Na,Wang Peng,Yue Xiqing,Xiao Zhigang
β-Sitosterol (Sit) and stearic acid (SA) were combined at varying ratios (w/w) and added to sunflower oil (SFO) at the concentration of 20 g/100 g oil for preparing edible fat-like oleogel. The oleogel was characterized using an optical microscope, Fourier transform infrared spectroscopy (FTIR), X-ray diffractometer (XRD), differential scanning calorimeter, and texture analyzer. The oil-binding capacity, melting temperature, and firmness of the oleogel increased with the increase in the amount of SA in the gelator combination (Sit:SA, w/w). The microscopic analysis showed that the gel network formed based on the crystallization and self-organization of gelator molecules, and both gelators showed an independent crystalline behavior in the oleogel. In addition, the FTIR spectra showed that the gel network formed via physical entanglements and was stabilized by non-covalent interactions such as hydrogen bonding. Furthermore, XRD diffraction patterns indicated high lateral packing of molecular layers in oleogel prepared with the Sit and SA combination compared with oleogel prepared with a single gelator. On the other hand, for studying the effect of varying concentrations of gelator combinations, the Sit3:SA2 (w/w) combination was added to SFO at concentrations of 10, 15, 20, 25, and 30 g/100 g oil. Specific characteristics such as the oil-binding capacity and firmness of the oleogel improved as the concentration of the gelator combination (Sit3:SA2) increased from 10 up to 30 g/100 g oil. Therefore, it can be concluded that the saturated fat alternative oleogel can be prepared from SFO with a specific Sit and SA combination ratio and concentration.
研究领域:
食品科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2023
·
IF 4.6
Li Zheng,Song Luo,Sijie Yang
Carbon steel is a widely used metallic material. It is prone to corrosion. In this study, we designed and fabricated a superhydrophobic layer with corrosion resistance for protection of carbon steel substrate. Multiple layers were formed that acted as barriers to protect the substrate from corrosion. This superhydrophobic layer reduced the contact area between the substrate and the corrosive medium owing to the superhydrophobicity. The experimental results showed that a copper layer uniformly covered the carbon steel substrate, and the outer surface of the copper layer was converted into copper oxide , which had a multi-scale structure. The Cu/CuO double layer was modified with stearic acid (SA) to form a Cu/CuO@SA superhydrophobic layer. The superhydrophobic layer exhibited a high water contact angle (up to 160°) and a low sliding angle (<3°). The superhydrophobic layer also exhibited repulsive effect to salt, acidic and alkaline solutions. Atmospheric stability test and UV irradiation test were conducted and the results indicated that the superhydrophobic layer was stable throughout the test period. The corrosion potential of the superhydrophobic sample was −0.18 V and the corrosion current density was 7.72 × 10 −7 A cm −2 , which was one order of magnitude lower than that of the carbon steel substrate. These results indicate that the superhydrophobic sample had a low corrosion tendency and corrosion rate. The polarization resistance and impedance modulus of the superhydrophobic sample were two orders of magnitude higher than the bare steel sample, indicating corrosion resistance and effective protection to the carbon steel substrate.
研究领域:
材料科学
·
腐蚀与防护
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）